1. Field of the Invention
The present invention relates to an arctic drill ship, and more particularly, to an arctic drill ship in which a weather tight structure minimizing the influence of outside air on a drilling operation in polar regions can be installed economically and easily and a structure causing a disturbance in the drilling work area is minimized.
2. Description of the Related Art
Generally, a drill ship is a generic term for ships that explore and drill marine resources such as oil or gas, and examples of the drill ship include a fixed type platform, a semi-submersible drill ship, and so on.
With the rapid development of technologies necessary to explore and drill oil and natural gas buried under the seabed, the working area of the drill ship has expanded from a shallow area such as a continental shelf having a depth of about 200 m to an area having a poor environment such as a deep sea or a polar region having a depth of 2,000 m or more.
FIG. 1 is a cross-sectional view illustrating a conventional drill ship. In the conventional drill ship 10, as illustrated in FIG. 1, a drill floor 12 is provided on a deck 12 of a hull 11, and a derrick 13 is fixed to the drill floor 12. The derrick 13 is a large complicated structure provided with beams and a variety of drilling equipments. A large moonpool 14 such a drill well is formed in the hull 11 in order for installation of drilling equipments.
In the case where such a conventional drill ship is operated in a polar region, the drilling equipment and the workspace are exposed to a low-temperature outside air and thus it is difficult to perform the drilling operation. Therefore, it is necessary to enclose the drilling equipment and the workspace such that they are not exposed to outside air.
However, in the case of the drill ship, main drilling equipments are extensively disposed in a rig floor, a hurricane deck, and a moonpool zone, it is difficult to enclose the drilling work area through a hull structure of a conventional drill ship. It is uneconomical and there is an unavoidable problem in that structures causing interference dangers during operations are disposed, when considering drilling operation characteristics.